81404045 has 4 divisors (see below), whose sum is σ = 97684860. Its totient is φ = 65123232.

The previous prime is 81404027. The next prime is 81404111. The reversal of 81404045 is 54040418.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 59182249 + 22221796 = 7693^2 + 4714^2 .

It is a cyclic number.

It is not a de Polignac number, because 81404045 - 2⁶ = 81403981 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8140400 + ... + 8140409.

It is an arithmetic number, because the mean of its divisors is an integer number (24421215).

Almost surely, 2^81404045 is an apocalyptic number.

It is an amenable number.

81404045 is a deficient number, since it is larger than the sum of its proper divisors (16280815).

81404045 is a wasteful number, since it uses less digits than its factorization.

81404045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16280814.

The product of its (nonzero) digits is 2560, while the sum is 26.

The square root of 81404045 is about 9022.4190215263. The cubic root of 81404045 is about 433.3931025381.

The spelling of 81404045 in words is "eighty-one million, four hundred four thousand, forty-five".